thurman



(No Model.)v

` R. W. THURMAN.

REMOVABLE PERMUTATION LOCK.

` No. 257,626. l y Patented MayQ, 1882.

N. PETERS) Pnuwwwgnpmr, wamingm. o. c.

UNITED vSTATES g PATENT OFFICE.

ROBERT W. 'IHURMAN, OF LYNOHBURG, VIRGINIA.

REMovABLE PERM uTATloN-LOCK.

SPECIFICATION forming part of Letters Patent No. 257,626, dated May .9, 1882. Application filed March 16, 1882. (No model.)

To all whom it may concern Be it known that I, ROBERT W. THURMAN, a citizen of the United States of America, residing at Lynchburg, in the county of Gampbell and State of Virginia, have invented certain new and useful Improvements in Removable Permutation-Locks; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings,and to letters or gures of reference marked there on, which form a part of this specification.

The object of my present invention (which is an improvement on my former Patent No. 252,386) is to secure a permutation-lock in the door to which it is to be applied in a manner so strong and simple that while offering great .resistance to attempts at dislodgment it may readily be removed by the employment of dcvices arranged for that purpose.

In the accompanying drawings,.in which similarletters of reference indicate corresponding parts, Figure l is afront view of a portion ot' a door from which my lock has been removed. Fig. 2 is a side view of my lock-case, showing means for securing it inl position, and a partial view of the contained locks visible through the broken-away portions. Fig. 3 is .a section on line y y, Fig. 2.

In the drawings, A` A represent a cylindrical shell or case 0f metal, preferably constructed in two parts secured together, the front piece or part being somewhat larger in diameter than the rear, and formed with the screw-thread G on its outside. Each of these two parts contains a separate and distinct permutation-lock. The tumblers h of lock N are circular, and are formed with the notches h in their outer edge. The tumblers of lock O are of any known style that are circular 'in form. The spindles of both these locks are brought to the front end of the case, the spindie of the forward or secondarylock, N, being made hollow to permit thespindle B of the rear lock to be operated through it as though it were not there.

On the outer end of spindle B is the ordinary dial, D, operatin gas usual. Underneath,

concealed by dial D, is a smaller dial, S, for

operating the secondary lock N, which is otherwise unaffected by the ordinary operation, in the usual manner, of lock O. '.llhere is a slot, F, in the case A Af, extending as far forward as the last of the second set of tumblers, and of about the same width as the notches in the tumblers.v This slot may be made in4 two portions in different parts ofthe case, but is preferably placed as shown. That portion of slot F in the rear and smaller portion,A, of v springH is attached to pawl G near its pivotalpoint and holds it down. In the front end of cylinder A are'formed holes, in which may be fixed the pins q, by the application of any flat instrument to which, or of a wrench adapted.

to engage with the said holes, the pins being removed, the case A A may be manipulated.

In the orifice E of the door is secured a sleeve, E, provided on its inner surface with a female screw, G, coinciding with screw-thread G on the case A. This sleeve E'is secured to the door by iiange on its inner edge. In the female screw G is cut a groove, F', coinciding with grooveF and pawl C of cylinder A.

A safe, vault, or other door has ,an aperture in which the sleeve E is secured. The combination of lock N is set up and the pawlC is pressed by spring H into the notches thereof. In that condition the case A A is, by the aid of a wrench or lat bar and pins, screwed into the door, and when in position, by doggin g the tumblers of lock N the pawl G is thrown up into groove F', preventing the further turning of caseA A and securing it in its place. Vhen the lock is in place and the combination of lock O is set up throughdial D the door-bolts willslip in to the notches therein, and in so doing the door will be unlocked.

It will be seen from the foregoing that the secondary lock N, by means of which and its accessories the whole is secured in the door,is only intended for use should the ordinary lock, O,controlling the bolt-work, fail to operate, in

which case, by unlocking the lock N, the case H, in combination withlocksNO, spindles B b,

A Al may be unscrewed from the door and redials D S, and indented notched tumblers h,

paired or replaced. arranged to engage with the coincident screw- 15 Havingdescribedmyinvention,whatlclaim, thread and groove of sleeve E, as shown and 5 and desire to secure by Letters Patent, is described.

1.' 'lhe locksN Oand cylindrical case A A', In testimony whereof I affix my signature in oried with screwt-)thread G thlereon slo; presence of two witnesses.

, t erein, in com ination Wit 'paw an spring H, arranged to operate as and for the ROBERT W' THURMA'N' 1o purpose specified. Witnesses:

2. A removable lock consisting of slotted V G. R. LYMAN, serewthreaded case A A', pawl C, and spring Jos. CARNEY. 

